Suspension polymerization of pvc polymers and copolymers at reduced temperatures

ABSTRACT

This invention relates to vinyl chloride polymerization products and to the process of making such products comprising the steps of polymerizing in suspension and at temperatures below about 100* F. monomers consisting of at least 60 percent by weight of vinyl chloride in the presence of an organic peroxy compound, a reducing agent, and a metallic accelerator.

United States Patent Shen [451 June 6, 1972 [541 SUSPENSION POLYMERIZATION 0F 3,244,677 4/1966 Glazer ..260/86.3 PVC POLYMERS AND CQPOLYIVIERS 3,180,907 4/1965 Follett ..260/87.5 AT REDUCED TEMPERATURES 3,230,206 1/1966 Albert et a1 ..260/87.5

Inventor: Pink Kang Shen, Leominster, Mass.

Assignee: Borden, Inc., New York, NY.

Filed: Dec. 14, 1966 'Appl. No.: 601,557

US. Cl ..260/86.3, 260/785, 260/8081,

260/875, 260/928 Int. Cl ..C08f 3/30, C08f 15/24, C08f 15/06 Field of Search ..260/86.3, 87.5, 92.8 W, 78.5 CL

References Cited UNITED STATES PATENTS 10/ 1 962 Holdsworth "260/928 W Primary Examiner-Harry Wong, .lr. Att0rneyJordan J. Driks and John L. Sigalos [57] ABSTRACT 5 Claims, No Drawings SUSPENSION POLYMERIZATION F PVC POLYMERS ANlD COPOLYMERS AT REDUCED TEMPERATURES This invention relates to a suspension polymerization process for vinyl chloride and vinyl chloride with comonomers polyols such as polyoxy C -C alkylene glycols, methyl cellulose, gelatin, hydroxyethyl cellulose, and the like surfactants such as metallic salts of (S -C aliphatic fatty alcohol sulfates, fatty alcohol phosphates, paraffin sulfonate, and the like.

therefor, and more particularly to a low temperature suspen- 5 Chain modifiers can be included such as carbon tetrachloride, sion polymerization process for said monomers. trichloroethylene, benzene, toluene, butyraldehyde and those Suspension polymerization of vinyl chloride are known. customarily employed in the art. However, these polymerization processes require elevated The process comprises admixing in an aqueous medium at temperatures for polymerization to proceed at a reasonable suspending agent, catalyst, reducing agent, a chain modifier if rate, as above F desired, and the divalent metal ion in the form of its salt. The The instant invention provides a low temperature suspenadmixture is maintained in the temperature range below 100 sion polymerization process for vinyl chloride and vinyl F. and preferably between 50 F. 70 F. The system is purged chloride with comonomers therefor. of oxygen with nitrogen gas or other non-reactive gas such as Briefly stated, the present invention provides a suspension carbon dioxide since it has been found that oxygen inhibits polymerization process for vinyl chloride and vinyl chloride this reaction. The monomers are added under agitation condiwith comonomers therefor wherein the monomers are interlions and Polymerization Proceeds in theltel'nlmlinune range polymerized in the temperature range from th f i point stated. The reaction is considered substantially complete of the System up to about 100 R inthe presence of a peroxy when the pressure in the closed system has fallen, as for examcatalyst for polymerization, a reducing agent, and an acceleraple, fr m an initial pressure of about 28 psig at a polymerizator of suspension polymerization, namely, a divalent metallic tion temperature of 70 F. to less than 5 psig. Generally, the ion. The invention will be more fully described in connection reaction is substantially complete in about 4 to 24 hours. with the suspension polymerization processof vinyl chloride The resulting polymer has been found to be of relatively in the presence of a peroxy catalyst, sodium bisulphite, and high molecular weight as the relative viscosity of the resin is in divalent copper ion. the range of about 3.0 3.2, as measured in 1 percent As to materials, the vinyl monomer comonomers of vinyl 25 cyclohexanone solution. chloride include vinyl acetate and other lower alkyl esters, As to proportions, the monomers consist of at least 60 per- C,C alkyl acrylate and methacrylate esters; C -C aliphatic cent by weight of vinyl chloride. The other additives are used esters of alpha-beta unsaturated di-carboxylic acids such as in their usual proportion as shown in Table l. itaconic acid. Also useful are alpha-chloro acrylic, alpha- As to proportions the following table shows proportional bromo acrylic, alpha-fluoroacrylic, and the like acids. ranges of the primary components set forth in columns as Generally, the proportion of vinyl chloride is at least 60 per- Recommended which provide the optimum range of proporcent by weight. Good results have been obtained with an intertions for the best results, and the Illustrative column which polymer of 90 percent by weight of vinyl chloride and 10 perprovides an ex anded range in which the degree of efficiency cent by weight of 2-ethyl hexyl acrylate. Peroxy catalyst for of the invention is reduced. Proportions greater than the lllusethenoid bond polymerization known in the art are readily trated range are considered economically unnecessary, and used to advantage in this process. Examples include t-butyl lower than said range are ineffective for the purpose required.

peroxy-pivalerate, isopropyl-di-peroxy carbonate, lauryl peroxide, hydrogen peroxide, benzoyl peroxide bis-2-4- dichloro benzoyl chloride, di-l-naphthoyl peroxide, t-butyl TABLEI hydroperoxide and the like. Also useful are azo-bis-isobu- Material Pans for 100 pans of Mommars I tyronitrile and the salts of peroxy-disulfuric acid or otherwise Il i Recommended known as water-soluble inorganic persulfates. These include potassium persulfate, ammonium persulfate, sodium persuspending agent .l l 0 2E5 sulfate and Catalyst .os-.5 .15-.25 The reducing agent is preferably sodium bisulfite for reason Reducing Agent 01 ,5 2 4 of convenience, however, other water-soluble agents known in Accelerator 0005-003 001-902 the art may be used to advantage. These include ascorbic acid, potassium bisulfite, ammonium bisulfite, sodium sulfite, sodium h d lfit and the like, In the examples that follow and elsewhere herein, propor- As to the accelerator of suspension polymerization, the tions are expressed as parts y Weight unless Specifically Stated divalent metallic ion, the metals are selected from the group t0 the Contraryconsisting of copper, mercury, barium, calcium, cadmium, zinc, nickel and cobalt. These ions are included in the suspen- EXAMPLE I sion polymerization medium to best advantage as a metallic salt, as for example cupric chloride, cupric sulfate,'cupric Suspension polymers of vinyl chloride and 2-ethyl-hexyl acetate, and the like. acrylate were prepared in accordance with the preferred Other additives which can be added to the polymerization method. The polymerization temperature was maintained at admixture include suspending agents such as fully and parabout 61 F. and the polymerization time was terminated after tially hydrolyzed polyvinyl alcohol; polyalkoxyalkylene 18 hours.

TABLE II Water, g 70 70 70 70 70 70 Monomers:

V01, g 28.5 28.5 28.5 28.5 28.5 28.5 28. 5 2-ethyl-hexy1 acrylato, g 1.5 1. 5 1.5 1. 5 1. 5 1. 5 1.5 Pluronlc ill-68, percent on monomer. 0.3 0. 3 0. 3 0. 3 0.3 0.3 0. 3 Lupersol 11, percent on monomer .00 .06 .06 .06 .06 00 .06 Sodium bisulfite, percent on monomer. 05 l 05 .60 50 m. CuCl2.2HzO,percent on monomcru. .0003) 00030 00030 00039 000.50 Results after 18 hrs., percent 30 10 1 Pluronlc F-68, a polyoxyethylene-p0lypropylene glycol non-ionic surfactant. 2 Lupersol 11, a 75% solution of t-butyl peroxy-pivalerato lll mlneral spirlt (catalyst).

3 N0 polymer.

From the above results, it can be seen that:

l. Lupersol 11 itself alone cannot induce polymerization at this temperature (No. l).

2. Lupersol ll Nal-lSQ. cannot induce polymerization quickly (No. 6).

3. Lupersol ll CuCl -2H O cannot induce polymerization (No. 7).

4. Lupersol ll Nal-lSO: CuCl,-2H O accelerates the polymerization very rapidly (No. 2, 3, 4, and No. 5 With a sufficient level of NaHSO and CuCI -ZH O, polymerization Proceeds to completion while a control does not polymerize at all. (No. l

5. Traces of copper is essential in accelerating the reaction.

(Nos. 2,3,4, and 5 vs. No. 6).

EXAMPLE II Suspension polymers as in Example i were prepared at a temperature of 64 F. and 12 hours.

TABLE III Water, g 70 70 70 70 70 Monomers, g.:

Vinyl chloride 30 30 28. 5 25. 5 30. 2-ethyl liexyl acrylate Vinyl acetate 1. 4. 5 Elvanol 50-42, percent; on

monomer .25 .25 .25 .25 .25 IPP, percent on monomer .06 .06 .06 .06 .06 NtIHSO percent on 1110110111. .50 .50 .50 .50 'Irlchloroethylene, percent on monomer. 1. 0 1. 0 1. 0 1.0 CuCh-ZHQO t on monomer 0003 000.5 0003 0003 Polymer formation, pel'cent. 100 95 95 1 Blow-up.

EXAMPLE Ill Various metallic ions were tried in suspension polymerizations as described in Example I. Polymerization temperature was 100 F. and time was 19 hours. In all runs the following proportions were used:

It is noted that quadri-valent tin has no significant effect on this process.

The suspension polymers made by this process have utility in areas well-known in the art, as for example in producing plastic products such as sound records, upholstery material, etc. These products are generally made by drying the polymer, blending with a plasticizer, and extrusion or molding to the shape desired.

It will be understood that it is intended to cover all changes and modifications of the examples of the invention herein chosen for the purpose of illustration which do not constitute departures from the spirit and scope of the invention.

lclaim:

1. A process for low temperature suspension polymerization of monomers consisting of at least 60 percent by weight of vin l chloride consisting essentially of the steps of:

. combining in an aqueous me mm a;

a. suspending agent;

b. polymerization catalyst for said monomers selected from the group consisting of organic peroxy compounds and water-soluble inorganic persulphate compounds; and

c. a divalent metallic ion accelerator selected from the group consisting of copper, mercury, barium, calcium, cadmium, zinc, nickel and cobalt in a proportion between about 0.005 0.003 parts by weight of accelerator for parts of monomers, said ions being added in the form of a water-soluble salt; and

d. a reducing agent,

2. admixing into said aqueous medium monomers comprising at least 60 percent by weight of vinyl chloride, and

3. maintaining the temperature in said admixture in the range of above the freezing point of said admixture and up to 100 F. until said monomers are substantially polymerized.

2. The process of claim 1 wherein:

. said divalent metallic ion accelerator is selected from the group consisting of copper, mercury, barium, calcium, cadmium, zinc, nickel and cobalt ions;

2. said monomers are selected from the group consisting of vinyl chloride, and vinyl chloride with monomers selected from the group consisting of lower alkyl vinyl esters,

C,Q, alkyl acrylate and methacrylate esters, and C,C,,

aliphatic esters of alphabeta unsaturated di-carboxylic acids; and,

said temperature range is between about 50 F 70 F.

. The process of claim 1 wherein;

. said catalyst is an organic peroxy compound and said reducing agent is sodium bisulfite.

4. The method of claim 2 wherein:

. said suspending agent is used in proportion of 0.1-1.0

parts by weight for 100 parts of monomers;

2. said catalyst is used in proportion of 0.15-0.25 parts by weight for 100 parts of monomers and said reducing agent is used in proportion of 0.0 l-0.5 parts by weight for 100 parts of monomers;

3. said metallic ion accelerator is in the form of cupric chloride salt;

4. said monomers consist essentially of vinyl chloride and 2- ethyl-hexyl acrylate; and

5. said temperature range is between about 50 F-70 F.

5. The process of claim 1, wherein the metallic ion accelerator is copper.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTIQN Patent No. 3 668 194 Dated Jun 6 1972 Ping Kang Shen Inventor(s) I It is certified that error appears in the above-identified patent and that said Letters Patentarefhereby corrected as shown below:

Column 1, line 3, beginning with "This invention relates" cancel all to and including "said monomers. in line 6, same column 1.

v Signed and sealed this 26th day of September l972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. I ROBERT GOTTSCHALK Attestlng Officer Commissioner of Patents FORM PC4050 uscoMM-oc 60376-P69 U.S. GOVERNMENT PRINTING OFFICE 2 I969 0-365334. 

2. The process of claim 1 wherein:
 2. said monomers are selected from the group consisting of vinyl chloride, and vinyl chloride with monomers selected from the group consisting of lower alkyl vinyl esters, C1-C8 alkyl acrylate and methacrylate esters, and C1-C8 aliphatic esters of alphabeta unsaturated di-carboxylic acids; and,
 2. said catalyst is used in proportion of 0.15-0.25 parts by weight for 100 parts of monomers and said reducing agent is used in proportion of 0.01-0.5 parts by weight for 100 parts of monomers;
 2. admixing into said aqueous medium monomers comprising at least 60 percent by weight of vinyl chloride, and
 3. maintaining the temperature in said admixture in the range of above the freezing point of said admixture and up to 100* F. until said monomers are substantially polymerized.
 3. said metallic ion accelerator is in the form of cupric chloride salt;
 3. said temperature range is between about 50* F - 70* F.
 3. The process of claim 1 wherein;
 4. The method of claim 2 wherein:
 4. said monomers consist essentially of vinyl chloride and 2-ethyl-hexyl acrylate; and
 5. said temperature range is between about 50* F-70* F.
 5. The process of claim 1, wherein the metallic ion accelerator is copper. 